Auto merge of rust-lang#7968 - Jarcho:manual_map_unsafe, r=xFrednet

Fix `manual_map` with unsafe functions

fixes: rust-lang#7820
changelog: Fix `manual_map` suggestion when used with unsafe functions and unsafe blocks

clippy_lints/src/manual_map.rs

@@ -2,7 +2,7 @@ use crate::{map_unit_fn::OPTION_MAP_UNIT_FN, matches::MATCH_AS_REF};
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::higher::IfLetOrMatch;
 use clippy_utils::source::{snippet_with_applicability, snippet_with_context};
-use clippy_utils::ty::{is_type_diagnostic_item, peel_mid_ty_refs_is_mutable};
+use clippy_utils::ty::{is_type_diagnostic_item, peel_mid_ty_refs_is_mutable, type_is_unsafe_function};
 use clippy_utils::{
  can_move_expr_to_closure, in_constant, is_else_clause, is_lang_ctor, is_lint_allowed, path_to_local_id,
  peel_hir_expr_refs, peel_hir_expr_while, CaptureKind,
@@ -11,7 +11,8 @@ use rustc_ast::util::parser::PREC_POSTFIX;
 use rustc_errors::Applicability;
 use rustc_hir::LangItem::{OptionNone, OptionSome};
 use rustc_hir::{
- def::Res, Arm, BindingAnnotation, Block, Expr, ExprKind, HirId, Mutability, Pat, PatKind, Path, QPath,
+ def::Res, Arm, BindingAnnotation, Block, BlockCheckMode, Expr, ExprKind, HirId, Mutability, Pat, PatKind, Path,
+ QPath, UnsafeSource,
 };
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
@@ -93,20 +94,20 @@ impl LateLintPass<'_> for ManualMap {
  return;
  }
 
- let some_expr = match get_some_expr(cx, some_expr, expr_ctxt) {
+ let some_expr = match get_some_expr(cx, some_expr, false, expr_ctxt) {
  Some(expr) => expr,
  None => return,
  };
 
  // These two lints will go back and forth with each other.
- if cx.typeck_results().expr_ty(some_expr) == cx.tcx.types.unit
+ if cx.typeck_results().expr_ty(some_expr.expr) == cx.tcx.types.unit
  && !is_lint_allowed(cx, OPTION_MAP_UNIT_FN, expr.hir_id)
  {
  return;
  }
 
  // `map` won't perform any adjustments.
- if !cx.typeck_results().expr_adjustments(some_expr).is_empty() {
+ if !cx.typeck_results().expr_adjustments(some_expr.expr).is_empty() {
  return;
  }
 
@@ -120,7 +121,7 @@ impl LateLintPass<'_> for ManualMap {
  None => "",
  };
 
- match can_move_expr_to_closure(cx, some_expr) {
+ match can_move_expr_to_closure(cx, some_expr.expr) {
  Some(captures) => {
  // Check if captures the closure will need conflict with borrows made in the scrutinee.
  // TODO: check all the references made in the scrutinee expression. This will require interacting
@@ -158,12 +159,14 @@ impl LateLintPass<'_> for ManualMap {
  };
 
  let body_str = if let PatKind::Binding(annotation, id, some_binding, None) = some_pat.kind {
- match can_pass_as_func(cx, id, some_expr) {
- Some(func) if func.span.ctxt() == some_expr.span.ctxt() => {
+ if_chain! {
+ if !some_expr.needs_unsafe_block;
+ if let Some(func) = can_pass_as_func(cx, id, some_expr.expr);
+ if func.span.ctxt() == some_expr.expr.span.ctxt();
+ then {
  snippet_with_applicability(cx, func.span, "..", &mut app).into_owned()
- },
- _ => {
- if path_to_local_id(some_expr, id)
+ } else {
+ if path_to_local_id(some_expr.expr, id)
  && !is_lint_allowed(cx, MATCH_AS_REF, expr.hir_id)
  && binding_ref.is_some()
  {
@@ -176,21 +179,23 @@ impl LateLintPass<'_> for ManualMap {
  } else {
  ""
  };
- format!(
-  "|{}{}| {}",
- annotation,
-  some_binding,
- snippet_with_context(cx, some_expr.span, expr_ctxt, "..", &mut app).0
- )
- },
+ let expr_snip = snippet_with_context(cx, some_expr.expr.span, expr_ctxt, "..", &mut app).0;
+ if some_expr.needs_unsafe_block {
+ format!("|{}{}| unsafe {{ {} }}", annotation, some_binding, expr_snip)
+ } else {
+ format!("|{}{}| {}", annotation, some_binding, expr_snip)
+ }
+ }
  }
  } else if !is_wild_none && explicit_ref.is_none() {
  // TODO: handle explicit reference annotations.
- format!(
- "|{}| {}",
- snippet_with_context(cx, some_pat.span, expr_ctxt, "..", &mut app).0,
- snippet_with_context(cx, some_expr.span, expr_ctxt, "..", &mut app).0
- )
+ let pat_snip = snippet_with_context(cx, some_pat.span, expr_ctxt, "..", &mut app).0;
+ let expr_snip = snippet_with_context(cx, some_expr.expr.span, expr_ctxt, "..", &mut app).0;
+ if some_expr.needs_unsafe_block {
+ format!("|{}| unsafe {{ {} }}", pat_snip, expr_snip)
+ } else {
+ format!("|{}| {}", pat_snip, expr_snip)
+ }
  } else {
  // Refutable bindings and mixed reference annotations can't be handled by `map`.
  return;
@@ -217,7 +222,9 @@ impl LateLintPass<'_> for ManualMap {
 fn can_pass_as_func(cx: &LateContext<'tcx>, binding: HirId, expr: &'tcx Expr<'_>) -> Option<&'tcx Expr<'tcx>> {
  match expr.kind {
  ExprKind::Call(func, [arg])
- if path_to_local_id(arg, binding) && cx.typeck_results().expr_adjustments(arg).is_empty() =>
+ if path_to_local_id(arg, binding)
+ && cx.typeck_results().expr_adjustments(arg).is_empty()
+ && !type_is_unsafe_function(cx, cx.typeck_results().expr_ty(func).peel_refs()) =>
  {
  Some(func)
  },
@@ -237,6 +244,11 @@ enum OptionPat<'a> {
  },
 }
 
+struct SomeExpr<'tcx> {
+ expr: &'tcx Expr<'tcx>,
+ needs_unsafe_block: bool,
+}
+
 // Try to parse into a recognized `Option` pattern.
 // i.e. `_`, `None`, `Some(..)`, or a reference to any of those.
 fn try_parse_pattern(cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>, ctxt: SyntaxContext) -> Option<OptionPat<'tcx>> {
@@ -257,7 +269,12 @@ fn try_parse_pattern(cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>, ctxt: SyntaxCon
 }
 
 // Checks for an expression wrapped by the `Some` constructor. Returns the contained expression.
-fn get_some_expr(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, ctxt: SyntaxContext) -> Option<&'tcx Expr<'tcx>> {
+fn get_some_expr(
+ cx: &LateContext<'tcx>,
+ expr: &'tcx Expr<'_>,
+ needs_unsafe_block: bool,
+ ctxt: SyntaxContext,
+) -> Option<SomeExpr<'tcx>> {
  // TODO: Allow more complex expressions.
  match expr.kind {
  ExprKind::Call(
@@ -266,15 +283,24 @@ fn get_some_expr(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, ctxt: SyntaxConte
  ..
  },
  [arg],
- ) if ctxt == expr.span.ctxt() && is_lang_ctor(cx, qpath, OptionSome) => Some(arg),
+ ) if ctxt == expr.span.ctxt() && is_lang_ctor(cx, qpath, OptionSome) => Some(SomeExpr {
+ expr: arg,
+ needs_unsafe_block,
+ }),
  ExprKind::Block(
  Block {
  stmts: [],
  expr: Some(expr),
+ rules,
  ..
  },
  _,
- ) => get_some_expr(cx, expr, ctxt),
+ ) => get_some_expr(
+ cx,
+ expr,
+ needs_unsafe_block || *rules == BlockCheckMode::UnsafeBlock(UnsafeSource::UserProvided),
+ ctxt,
+ ),
  _ => None,
  }
 }

tests/ui/manual_map_option_2.fixed

@@ -47,4 +47,14 @@ fn main() {
  let _ = s.as_ref().map(|x| {
  if let Some(ref s) = s { (x.clone(), s) } else { panic!() }
  });
+
+ // Issue #7820
+ unsafe fn f(x: u32) -> u32 {
+ x
+ }
+ unsafe {
+ let _ = Some(0).map(|x| f(x));
+ }
+ let _ = Some(0).map(|x| unsafe { f(x) });
+ let _ = Some(0).map(|x| unsafe { f(x) });
 }

tests/ui/manual_map_option_2.rs

@@ -53,4 +53,23 @@ fn main() {
  }),
  None => None,
  };
+
+ // Issue #7820
+ unsafe fn f(x: u32) -> u32 {
+ x
+ }
+ unsafe {
+ let _ = match Some(0) {
+ Some(x) => Some(f(x)),
+ None => None,
+ };
+ }
+ let _ = match Some(0) {
+ Some(x) => unsafe { Some(f(x)) },
+ None => None,
+ };
+ let _ = match Some(0) {
+ Some(x) => Some(unsafe { f(x) }),
+ None => None,
+ };
 }

tests/ui/manual_map_option_2.stderr

@@ -39,5 +39,35 @@ LL + if let Some(ref s) = s { (x.clone(), s) } else { panic!() }
 LL ~ });
  |
 
-error: aborting due to 2 previous errors
+error: manual implementation of `Option::map`
+ --> $DIR/manual_map_option_2.rs:62:17
+ |
+LL | let _ = match Some(0) {
+ | _________________^
+LL | | Some(x) => Some(f(x)),
+LL | | None => None,
+LL | | };
+ | |_________^ help: try this: `Some(0).map(|x| f(x))`
+
+error: manual implementation of `Option::map`
+ --> $DIR/manual_map_option_2.rs:67:13
+ |
+LL | let _ = match Some(0) {
+ | _____________^
+LL | | Some(x) => unsafe { Some(f(x)) },
+LL | | None => None,
+LL | | };
+ | |_____^ help: try this: `Some(0).map(|x| unsafe { f(x) })`
+
+error: manual implementation of `Option::map`
+ --> $DIR/manual_map_option_2.rs:71:13
+ |
+LL | let _ = match Some(0) {
+ | _____________^
+LL | | Some(x) => Some(unsafe { f(x) }),
+LL | | None => None,
+LL | | };
+ | |_____^ help: try this: `Some(0).map(|x| unsafe { f(x) })`
+
+error: aborting due to 5 previous errors